System and method for inductive charging of portable devices

Patent metadata

Field	Value
Publication number	US-11569685-B2
Application number	US-202217850700-A
Country	US
Kind code	B2
Filing date	Jun 27, 2022
Priority date	Jan 31, 2006
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

An electronic device having an inductive power transfer system to transfer power to a portable device is disclosed. The electronic device includes a first inductive coil for power transfer using an alternating magnetic field. The electronic device further includes a permanent magnet structure for creating a separable magnetic attachment between the electronic device and the portable device having a second inductive coil for inductive power transfer. The permanent magnet structure is positioned around an outer perimeter of the first inductive coil to align the first inductive coil with the second inductive coil in the portable device for inductive power transfer. The permanent magnet structure includes one or more discontinuous arc-shaped permanent magnets assembled to form a full or partial ring shape that includes a gap to impede eddy current generation in the permanent magnet structure by the alternating magnetic field during inductive power transfer.

First claim

What is claimed is:

1. An electronic device having an inductive power transfer system to transfer power to a portable device, the electronic device comprising:
a substantially planar first inductive coil for inductive power transfer using an alternating magnetic field in a direction substantially perpendicular to the plane of the first inductive coil; and
a permanent magnet structure for creating a separable magnetic attachment between the electronic device and the portable device having a second inductive coil for inductive power transfer,
wherein the permanent magnet structure is positioned around an outer perimeter of the first inductive coil to align the first inductive coil with the second inductive coil in the portable device for inductive power transfer, and
wherein the permanent magnet structure comprises one or more discontinuous arc-shaped permanent magnets assembled to form a full or partial ring shape that includes a gap to impede eddy current generation in the permanent magnet structure by the alternating magnetic field during inductive power transfer.

2. The electronic device of claim 1 ,
wherein the electronic device is capable of rotating with respect to the portable device while maintaining the magnetic attachment between the electronic device and the portable device when the electronic device and the portable device are aligned for inductive power transfer.

3. The electronic device of claim 2 , wherein the permanent magnet structure further comprises a bar magnet positioned outside the perimeter of the first inductive coil to fix the electronic device at a predetermined rotational position with respect to the portable device.

4. The electronic device of claim 1 , wherein the permanent magnet structure comprises Neodymium, Iron, and Boron.

5. The electronic device of claim 1 , wherein the electronic device includes a rechargeable battery and an inductive charging receiver for receiving inductive power to charge the rechargeable battery, and wherein the electronic device is a mobile device.

6. The electronic device of claim 1 , wherein the inductive power transfer system of the electronic device is an inductive charger for transmitting inductive power.

7. The electronic device of claim 1 , wherein the inductive power transfer system of the electronic device is configured for:
holding and charging the portable device in a vehicle; and
receiving power from the vehicle for its operation.

8. The electronic device of claim 1 , wherein the first inductive coil includes a magnetic core of ferromagnetic material within a central area of the first inductive coil and the electronic device further comprises a Near Field Communication (NFC) coil and circuitry for communication of data using the NFC coil.

9. The electronic device of claim 1 , wherein the electronic device is a storage case for a Bluetooth headset that includes a rechargeable battery that is configured to receive charge through inductive power transfer via the first inductive coil and is further configured to charge the Bluetooth headset when stored inside the storage case.

10. The electronic device of claim 1 , wherein the inductive power transfer system of the electronic device is an inductive charger and wherein the electronic device further comprises a drive circuit configured to operate the inductive power transfer system in a Zero Voltage Switching (ZVS) mode or a Zero Current Switching (ZCS) mode,
wherein the drive circuit is configured to drive the first inductive coil in a frequency region in which reducing the operating frequency results in increased transferred power to the portable device during inductive power transfer.

11. The electronic device of claim 1 , further comprising a magnetic sensor that detects the presence of a magnet in the portable device when the magnet in the portable device is proximate to the electronic device, wherein the electronic device is configured such that detection of the portable device by the magnetic sensor initiates inductive power transfer with the portable device.

12. The electronic device of claim 1 , wherein the electronic device comprises a first drive circuit, a first sense circuit, and a first communication and control circuit forming a first inductive charger module to inductively charge the portable device,
wherein the first inductive charger module is configured to interconnect mechanically and electrically with a second inductive charger module, separate from the first inductive charger module, that has a substantially planar second inductive charger coil, a second permanent magnet structure, a second drive circuit, a second sense circuit, and a second communication and control circuit to charge a second portable device, and
wherein the first inductive charger module is configured to share electrical power with the second inductive charger module when interconnected.

13. The electronic device of claim 1 , further comprising:
a rechargeable battery; and
an inductive charging receiver electrically coupled to the first inductive coil for receiving power inductively from the portable device to charge the rechargeable battery,
wherein in a first mode, the electronic device is configured to transmit power inductively using the first inductive coil, and
wherein in a second mode, the electronic device is configured to receive power inductively through the first inductive coil.

14. The electronic device of claim 1 , further comprising an enclosure that houses the electronic device,
wherein the enclosure comprises a surface for inductive power transfer,
wherein the surface for inductive power transfer includes a first layer comprising metal positioned proximate to the first inductive coil, and
wherein the first layer covers an area positioned around an outer perimeter of the first inductive coil but does not cover the first inductive coil.

15. The electronic device of claim 1 , wherein the electronic device further comprises a shield that includes a copper layer and a high heat conductivity layer, wherein the shield is positioned proximate to the first inductive coil, and wherein the shield covers an area around an outer perimeter of the first inductive coil to disperse a portion of heat generated during inductive power transfer.

16. The electronic device of claim 1 , further comprising:
a surface for inductive power transfer,
wherein the first inductive coil has a substantially planar first side closest to the surface of the electronic device, and
wherein the first inductive coil comprises a substantially planar metallic spiral-shaped conductor; and

a shield positioned proximate the first side of the first inductive coil and covering the metallic spiral-shaped conductor, such that the shield is between the metallic spiral-shaped conductor of the first side of the first inductive coil and the surface,
wherein the shield comprises a metal layer with thickness in a range of 1 micrometer to 70 micrometers and wherein the shield has a relative permeability of one.

17. The electronic device of claim 16 , wherein the shield comprises at least one of copper and aluminum material.

18. The electronic device of claim 16 , wherein the shield comprises at least one of silver and gold material.

19. The electronic device of claim 1 , wherein the electronic device further comprises:
a surface for inductive power transfer,
wherein the first inductive coil has a substantially planar first side closest to the surface of the electronic device, and
wherein the first inductive coil comprises a substantially plan

Assignees

• Mojo Mobility Inc

Inventors

• Partovi Afshin
• Sears Michael

Classifications

• G06F1/1683

  for the transmission of signal or power between the different housings, e.g. details of wired or wireless communication, passage of cabling · CPC title

• H02J7/025

  Electricity · mapped topic

• H02J50/10 Primary

  using inductive coupling · CPC title

• H02J7/00041

  Electricity · mapped topic

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title